mfd: add stmpe-i2c driver

The stmpe mfds can be connected via i2c and spi. This driver provides the basic
infrastructure for the i2c kind. It can be added as a normal i2c-device in the
board code. To enable functions a platform_data struct has to be provided, that
describes what parts of the chip are to be used.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

drivers/mfd/Kconfig

@@ -33,4 +33,8 @@ config I2C_TWL6030
 	select I2C_TWLCORE
 	bool "TWL6030 driver"
 
+config I2C_STMPE
+	depends on I2C
+	bool "STMPE-i2c driver"
+
 endmenu

drivers/mfd/Makefile

@@ -6,3 +6,4 @@ obj-$(CONFIG_I2C_LP3972) += lp3972.o
 obj-$(CONFIG_I2C_TWLCORE) += twl-core.o
 obj-$(CONFIG_I2C_TWL4030) += twl4030.o
 obj-$(CONFIG_I2C_TWL6030) += twl6030.o
+obj-$(CONFIG_I2C_STMPE) += stmpe-i2c.o

drivers/mfd/stmpe-i2c.c

@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2012 Pengutronix
+ * Steffen Trumtrar <s.trumtrar@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <common.h>
+#include <init.h>
+#include <driver.h>
+#include <xfuncs.h>
+#include <errno.h>
+
+#include <i2c/i2c.h>
+#include <mfd/stmpe-i2c.h>
+
+#define DRIVERNAME		"stmpe-i2c"
+
+#define to_stmpe(a)		container_of(a, struct stmpe, cdev)
+
+int stmpe_reg_read(struct stmpe *stmpe, u32 reg, u8 *val)
+{
+	int ret;
+
+	ret = i2c_read_reg(stmpe->client, reg, val, 1);
+
+	return ret == 1 ? 0 : ret;
+}
+EXPORT_SYMBOL(stmpe_reg_read)
+
+int stmpe_reg_write(struct stmpe *stmpe, u32 reg, u8 val)
+{
+	int ret;
+
+	ret = i2c_write_reg(stmpe->client, reg, &val, 1);
+
+	return ret == 1 ? 0 : ret;
+}
+EXPORT_SYMBOL(stmpe_reg_write)
+
+int stmpe_set_bits(struct stmpe *stmpe, u32 reg, u8 mask, u8 val)
+{
+	u8 tmp;
+	int err;
+
+	err = stmpe_reg_read(stmpe, reg, &tmp);
+	tmp = (tmp & ~mask) | val;
+
+	if (!err)
+		err = stmpe_reg_write(stmpe, reg, tmp);
+
+	return err;
+}
+EXPORT_SYMBOL(stmpe_set_bits);
+
+static ssize_t stmpe_read(struct cdev *cdev, void *_buf, size_t count, loff_t offset, ulong flags)
+{
+	struct stmpe *stmpe = to_stmpe(cdev);
+	u8 *buf = _buf;
+	size_t i = count;
+	int err;
+
+	while (i) {
+		err = stmpe_reg_read(stmpe, offset, buf);
+		if (err)
+			return (ssize_t)err;
+		buf++;
+		i--;
+		offset++;
+	}
+
+	return count;
+}
+
+static ssize_t stmpe_write(struct cdev *cdev, const void *_buf, size_t count, loff_t offset, ulong flags)
+{
+	struct stmpe *stmpe = to_stmpe(cdev);
+	const u8 *buf = _buf;
+	size_t i = count;
+	int err;
+
+	while (i) {
+		err = stmpe_reg_write(stmpe, offset, *buf);
+		if (err)
+			return (ssize_t)err;
+		buf++;
+		i--;
+		offset++;
+	}
+
+	return count;
+}
+
+static struct file_operations stmpe_fops = {
+	.lseek	= dev_lseek_default,
+	.read	= stmpe_read,
+	.write	= stmpe_write,
+};
+
+static int stmpe_probe(struct device_d *dev)
+{
+	struct stmpe_platform_data *pdata = dev->platform_data;
+	struct stmpe *stmpe_dev;
+	struct stmpe_client_info *i2c_ci;
+
+	if (!pdata) {
+		dev_dbg(dev, "no platform data\n");
+		return -ENODEV;
+	}
+
+	stmpe_dev = xzalloc(sizeof(struct stmpe));
+	stmpe_dev->cdev.name = DRIVERNAME;
+	stmpe_dev->client = to_i2c_client(dev);
+	stmpe_dev->cdev.size = 191;		/* 191 known registers */
+	stmpe_dev->cdev.dev = dev;
+	stmpe_dev->cdev.ops = &stmpe_fops;
+	stmpe_dev->pdata = pdata;
+	dev->priv = stmpe_dev;
+
+	i2c_ci = xzalloc(sizeof(struct stmpe_client_info));
+	i2c_ci->stmpe = stmpe_dev;
+	i2c_ci->read_reg = stmpe_reg_read;
+	i2c_ci->write_reg = stmpe_reg_write;
+
+	if (pdata->blocks &= STMPE_BLOCK_GPIO)
+		add_generic_device("stmpe-gpio", DEVICE_ID_DYNAMIC, NULL, 0, 0, IORESOURCE_MEM, i2c_ci);
+
+	devfs_create(&stmpe_dev->cdev);
+
+	return 0;
+}
+
+static struct driver_d stmpe_driver = {
+	.name  = DRIVERNAME,
+	.probe = stmpe_probe,
+};
+
+static int stmpe_init(void)
+{
+        register_driver(&stmpe_driver);
+        return 0;
+}
+
+device_initcall(stmpe_init);

include/mfd/stmpe-i2c.h

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2012 Pengutronix
+ * Steffen Trumtrar <s.trumtrar@pengutronix.de>
+ *
+ * This file is released under the GPLv2
+ *
+ */
+
+#ifndef __ASM_ARCH_STMPE_H
+#define __ASM_ARCH_STMPE_H
+
+enum stmpe_revision {
+	STMPE610,
+	STMPE801,
+	STMPE811,
+	STMPE1601,
+	STMPE2401,
+	STMPE2403,
+	STMPE_NBR_PARTS
+};
+
+enum stmpe_blocks {
+	STMPE_BLOCK_GPIO	= 1 << 0,
+	STMPE_BLOCK_KEYPAD      = 1 << 1,
+	STMPE_BLOCK_TOUCHSCREEN = 1 << 2,
+	STMPE_BLOCK_ADC         = 1 << 3,
+	STMPE_BLOCK_PWM         = 1 << 4,
+	STMPE_BLOCK_ROTATOR     = 1 << 5,
+};
+
+struct stmpe_platform_data {
+	enum	stmpe_revision	revision;
+	enum	stmpe_blocks	blocks;
+	int			gpio_base;
+};
+
+struct stmpe {
+	struct cdev		cdev;
+	struct i2c_client	*client;
+	struct stmpe_platform_data *pdata;
+};
+
+struct stmpe_client_info {
+	struct stmpe *stmpe;
+	int (*read_reg)(struct stmpe *stmpe, u32 reg, u8 *val);
+	int (*write_reg)(struct stmpe *stmpe, u32 reg, u8 val);
+};
+
+int stmpe_reg_read(struct stmpe *priv, u32 reg, u8 *val);
+int stmpe_reg_write(struct stmpe *priv, u32 reg, u8 val);
+int stmpe_set_bits(struct stmpe *priv, u32 reg, u8 mask, u8 val);
+
+#endif /* __ASM_ARCH_STMPE_H */